Psoriasis – symptoms, causes and treatment

Symptoms of psoriasis

The most common symptom is well-defined red patches of skin covered with white or silvery scales. The patches most often appear symmetrically on the elbows, knees, lower back and scalp, but they can occur anywhere on the body. Many people experience itching and scaling, which may worsen during cold and dry periods.

Nail psoriasis

Nail psoriasis can cause pitting, discolouration or separation of the fingernails and toenails and is present in up to half of all people with psoriasis. Psoriasis of the scalp causes pronounced scaling and is often mistaken for severe dandruff or seborrhoeic eczema.

Guttate psoriasis

Guttate psoriasis appears as many small, drop-shaped red spots across large areas of the body and is particularly common in children and young people. Psoriasis in skin folds — under the breasts, in the groin and between the buttocks — usually does not have the typical scaling and can easily be mistaken for a fungal infection or eczema.

Psoriatic arthritis

In some patients, psoriasis also affects the joints. Psoriatic arthritis causes pain, swelling and stiffness, most commonly in the fingers, toes and spine. It can be erosive, meaning that it may damage joint cartilage if it is not diagnosed and treated in time.

Causes of psoriasis

Psoriasis is an immune-mediated disease. The immune system triggers an inflammatory reaction in the skin that significantly accelerates the turnover of skin cells. Immature cells then build up on the surface of the skin and form the characteristic plaques.

The condition has a strong hereditary component. If both parents have psoriasis, the risk of inheriting it may be as high as 50%. Psoriasis shares genetic features with other autoimmune conditions and is now considered a systemic inflammatory disease rather than simply a skin condition.

A number of factors can trigger or worsen psoriasis. Bacterial throat infections caused by streptococci are a common trigger, particularly for guttate psoriasis in children and young people. Stress, certain medications — including beta-blockers and lithium — skin trauma, smoking and being overweight are all well-documented factors that can worsen the condition. Cold and dry weather typically aggravates psoriasis, while sunlight provides relief for many people.

Examination and diagnosis

Psoriasis is diagnosed clinically by a specialist in dermatology based on the appearance of the skin and nails, the patient’s medical history and family history. In most cases, the diagnosis can be made confidently based on the clinical examination alone. In cases of uncertainty — or when a fungal nail infection needs to be ruled out — a skin biopsy may be performed.

The severity of psoriasis is assessed according to how much of the body is affected.

• Mild psoriasis affects less than 3% of the skin surface
• Moderate psoriasis affects 3–10%
• Severe psoriasis affects more than 10%

Approximately one quarter of all patients have moderate to severe psoriasis.

Psoriasis can be mistaken for seborrhoeic eczema, lichen planus and fungal infections. An accurate diagnosis is essential in order to choose the appropriate treatment.

If there are signs of joint involvement — such as morning stiffness, swollen fingers or toes, or pain in the spine — the assessment may include a rheumatological evaluation, blood tests and diagnostic imaging. Nail psoriasis is associated with an increased risk of psoriatic arthritis and should therefore always prompt an assessment of the joints.

Treatment of psoriasis

There is currently no treatment that permanently cures psoriasis, but effective treatment options are available to achieve long-term improvement and control of symptoms at all levels of severity.

For mild to moderate psoriasis, topical treatment is usually the first choice. Combination treatments containing a vitamin D analogue and a corticosteroid are an evidence-based standard treatment. Daily skincare with a rich moisturiser is also an important part of treatment. Scalp psoriasis may be treated with psoriasis shampoo, gel or scalp ointment, as over-the-counter products are rarely sufficient for more pronounced disease.

For moderate to severe psoriasis, or when topical treatment is not sufficient, we refer patients to the appropriate treatment provider. This may include phototherapy or biological treatment. We ensure that the patient is referred onwards with a clear specialist assessment.

When should you see a doctor?

It is appropriate to seek assessment by a specialist if red patches on the skin are persistent or worsening, if scaling and itching interfere with sleep or daily life, if the fingernails or toenails have changed, or if topical treatment has not had sufficient effect within four to six weeks. Psoriasis in children should be assessed early, as the condition can often be mistaken for other skin conditions in younger patients.

If there are signs of joint involvement — such as pain, swelling or stiffness in the fingers, toes or back — it is important to seek medical attention promptly. Psoriatic arthritis can cause permanent joint damage if treatment is delayed.

Psoriasis at Charlottenlund Private Hospital



At Charlottenlund Private Hospital, our dermatologists offer assessment and individually tailored treatment for all forms of psoriasis, including plaque psoriasis, nail psoriasis, scalp psoriasis, guttate psoriasis and psoriasis in children.

One of our particular strengths is that we have specialists in both dermatology and rheumatology, allowing for coordinated assessment and treatment when psoriasis and psoriatic arthritis occur together.